Engine spark control



July 22,

B. WALKER ENGINE SPARK CONTROL Original Filed 001;. 4, 1965 ire 3,456,633 ENGINE SPARK CONTROL Brooks Walker, 1280 Columbus Ave., San Francisco, Calif. 94133 Continuation of application Ser. No. 492,498, Oct. 4, 1965. This application Jan. 24, 1968, Ser. No. 707,347

Int. Cl. F02p 5/10 US. Cl. 123117 7 Claims ABSTRACT OF THE DISCLOSURE A spark control for an internal combustion engine in which a spark retard device is combined with a spark advance mechanism to provide spark control at all engine speeds. A vacuum motor is arranged to move the spark control breaker plate. The motor comprises a housing having a diaphragm therein dividing the housing into two chambers. One chamber is constantly connected to the engine developed source of vacuum. The other chamber can be selectively connected to either engine developed suction or atmosphere. In one form of the invention the valve used for the selective connection is operated by the anti-percolator mechanism. In a second form of the invention the valve is operated by the foot throttle return spring.

This application is a continuation of my application Serial No. 492,498, filed October 4, 1965, and now abandoned.

This invention pertains to a spark control for an internal combustion engine, particularly for an engine used in a motor vehicle. In such a vehicle it is customary to have the distributor include a breaker plate which is rotatable for a limited degree of rotation by an engine intake suction operated spark advance (sometimes referred to as a vacuum controlled spark advance). The suction that operates this advance can be controlled by a passage in the carburetor that is passed over by the throttle butterfly when in the idle position and generally operates as shown and described in Glenns Auto Repair Manual, 1964 edition, page 375. Any other suitable control of the engine suction operated spark advance can be used for the advance control. The advance control is usually supplemented by the governor advance operating on the cam that operates the breaker, also as explained in said Glenns reference, page 375.

The object and novelty of this invention is the use of a single diaphragm with two different circuits for engine developed suction to operate otf the opposite sides of said diaphragm, the suction on the vacuum advance side acting in the conventional matter, as explained in said Glenns reference. The engine developed suction is valve controlled to act on the other side of said diaphragm after the carburetor throttle is in the engine idle position by the continuing motion of the throttle control linkage to operate a suitable valve to expose said other side of said diaphragm to engine developed suction to cause said breaker plate to rotate to an engine spark retard position for idle when the spark is moved back from a before dead center position of up to 10 degrees to an after top dead center position of 3 to 6 degrees A.T.D.C.

Another feature is the type of suction controlled valve used for this spark retard at engine idle wherein a single plunger is used to open the valve leading the suction to the said other side of said diaphragm in one position of said valve and simultaneously closing a bleed in said valve to atmospheric pressure. When said valve is in the other position the passage to the engine suction is closed off and the bleed is open so that atmospheric pressure is admitted to said other side of said diaphragm. By this means whenever the engine is operating at more than 3,455,633 Patented July 22, 1969 idle or with a partially open, full open or in between throttle position the normal vacuum operated spark advance can function through the action of said diaphragm without opposition from suction on the said other side of said diaphragm.

Another feature is to use a portion of a carburetor that moves as the throttle valve is closed, such as the antipercolator arm to operate the stem that opens the valve so that engine developed suction will provide a spark retard, such suction being controlled by a valve which is operated by the carburetor parts that move just as the throttle valve is closing. This last operation gives a spark retard effective just as the throttle moves to the idle position, whereas the first described operation gives the spark retard after the throttle valve has reached the idle position and the throttle linkage moves on beyond the engine idle throttle butterfly position.

With the just described construction, as the foot throttle moves slightly from the foot off position first the spark will move from the retard engine idle position to the normal engine idle timing of 6 to 10 degrees B.T.C. with a resulting increase in engine idle speed that will provide low speed cruises with the carburetor throttle still in the engine idle position.

Another feature is one in which the engine will have the normal spark advance even if operating well below 1000 r.p.m. with a cracked or partly open throttle which would not be the case with a spark advance control where the governor that advances the cam retards the spark more than normal at speeds below 1000 r.p.m. as is done by Chrysler in the clean air package distributor and carburetor arrangement for reduced exhaust smog.

Other features will be pointed out in the accompanying specification and claims.

I have illustrated my invention by way of example in the accompanying drawings, in which:

FIG. 1 is a plan view partly in section of a spark control device for an engine, showing one form of the invention.

FIG. 2 is a side view of a carburetor throttle linkage and part of an engine showing another form of the invention as pertains to the retard controlling valve operating mechanism in another form of the invention.

In all figures like numerals refer to corresponding parts.

In FIG. 1 I have shown a distributor housing 10, a cam 11, which operates breaker arm 12, which supports contact 12a, which contacts ground contact 13. Spring 14 urges contact 12a against ground contact 13 in the usual manner. Condenser 16 is connected by wire '17 to spring 14 to reduce arcing at points 12a and 13, as is conventional practice.

Breaker plate 20 is pivoted at pin 21 and supports condenser 16, ground point 13, movable arm 12 and point 12a. Spring anchor 14a which is insulated electrically from spring 14 and wire 17 goes to the primary of a coil not shown.

Arm 22 is pivotally attached to breaker plate 20 by pin 23; arm 22 is flexibly secured to shaft 25 by connection 25a.

Shaft 25 is slidably supported on bearing 26 which might be of nylon, etc. to make a reduced friction sliding support and a suction seal.

Washers 27 support diaphragm 28 and secure its center section to shaft 25.

The outer edges of diaphragm 28 are clamped between the edges of housing 30 as retained by the crimped edge of housing 31. Spring 33 is of such resistance as to give the desired spark advance with suction changes coming from fitting 35 acting on the spring 33 side of diaphragm 28 as described in said Glenns reference.

As the throttle is closed, anti-percolator operating arm 40 rises to open valve 41 to open port 42 in the cover plate 45 for the carburetor, not shown, but as shown in detail in said Glenns reference, page 296, see FIG. 22.

Rocker arm 47 has end 47a which bears on percolator valve operator 40. End 47b actuates valve stem 50 which carries ring 54 above and O ring 55 below, the center of valve 50a.

Ring 54 seats on seat 560 to shut oif suction from line 61 leading to the intake manifold of engine 9, as shown in FIG. 2.

In operation, when the throttle is open suction from line 37 of carburetor 8 controls the vacuum spark advance" as disclosed in said Glenns reference in a conventional manner. As the throttle closes, anti-percolator valve 41 rises by rod 40 rising. Rocker arm 47 valve stem 50 will lower opening valve 54 to admit suction from line 61 to be applied to line 60 to move diaphragm 28 away from spring 33 and move breaker plate clockwise around pin 21 to retard the spark at idle throttle position more than if acted on by engine suction through line 37 on the spring side of diaphragm 28.

In FIG. 2 I have shown an engine 9 on which is mounted a carburetor 8. A throttle arm 65 is attached to transmission shift control arm 66 (transmission not shown). Block 67 is pivotally mounted an arm 65 and slidably supports throttle operating rod 71. Collar 70 is secured to rod 71 as is collar 69. Spring 68 urges block 67 against block 70. However, after the throttle has reached the idle position foot throttle return spring 78 will compress lighter spring 68 to cause the end of rod 71 to abut against rocker arm 78 to push valve stem 50 in toward valve '56 to allow engine suction to act from line 61 to line 60 to act on the side of diaphragm 28 away from spring 33 to move breaker plate 20 clockwise about pivot 21 to cause the spark to be retarded from a B.T.D.C. position to A.T.D.C. position for improved combustion at idle and less unburned hydrocarbons in the exhaust.

Another feature is the normal advance of the spark as when the engine is lugging with a stick shift transmission and partly or fully open throttle at speeds below 1000 rpm. When a governor cam in the distributor is used, that retards the spark more than normal below 1000 rpm. for better anti-smog operation, such lugging may be at excessive retard with such a spark controlling governor cam. Therefore, the proposed spark retard is advantageous over the governor cam low speed retard.

Another feature is normal spark advance at low speed starter cranking when the throttle is cracked for better starting than with the governor cam low speed spark retard.

Throttle control arm 71 is operated by bell crank 73, rod 75 and arm 76 which is attached to foot pedal 77.

I have illustrated my invention in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. An internal combustion engine having a plurality of cylinders, air and fuel feeding means for feeding fuel to the cylinders, means for producing a spark in said cylinders for igniting the fuel therein, and means for controlling the timing of the spark, said latter means comprising a fluid operated motor, a linkage connected to said fuel feeding means for reducing the feed of fuel and air to engine idling quantity, and means operated by the linkage after the feed of fuel has been reduced to idling quantity to operate the motor for retarding the timing of the spark.

2. A device as defined in claim 1 further including means responsive to operation of the linkage for operating the motor to advance the timing of the spark before the feed of fuel and air is increased beyond idling quantity.

3. An internal combustion engine having a plurality of cylinders, a carburetor, a manifold for conducting a combustible charge from the carburetor to the cylinders, a distributor having a breaker plate for producing a spark in the cylinders, and means for controlling the timing of the spark, said means comprising a housing, a diaphragm connected to the walls of the housing dividing the housing into separate chambers, means connecting the diaphragm to pivot the breaker plate on movement of the diaphragm, and means to move the diaphragm comprising a conduit constantly connected to one of the chambers and a source of suction developed by the engine, a spring in said chamber for urging the diaphragm in one direction, a second conduit connected to the other chamber, a valve for connecting said second conduit to the intake manifold or to atmosphere, and means for operating the valve to'select connection of either said manifold or atmosphere.

4. A device as defined in claim 3 wherein the means for operating the valve comprises a stern connected to the valve, a spring for urging the valve in one direction to connect the second conduit to atmosphere, said carburetor having an anti-percolator operating arm, and means connecting said arm to the stem to move the valve in the opposite direction to connect the second conduit to the intake manifold.

5. A device as defined in claim 3 wherein the means for operating the valve comprises a stem connected to the valve, a spring for urging the valve in one direction to connect the second conduit to atmosphere, and means engaging the stem after the carburetor throttle is closed for urging the valve in the opposite direction to connect the second conduit to the intake manifold.

6. A device as defined in claim 5 wherein the means for urging the valve in the opposite direction comprises a rod, a throttle arm pivotally mounted on the carburetor, means limiting movement of the arm to a position in which the throttle in the carburetor is closed, means slidably mounting the rod on the arm, spring means urging the rod away from the stem, a spring urging the rod toward the stern against the force of the spring means, a foot pedal connected to the throttle arm, and means connecting the spring to the foot pedal to urge the pedal to throttle closed position.

7. An internal combustion engine having a plurality of cylinders, a carburetor, a manifold for conducting a combustible charge from the carburetor to the cylinders, a distributor and ignition system having means including a breaker plate for producing a spark in the cylinders, and means for controlling the timing of the spark, said means comprising a housing, means dividing the housing into separate chambers, means connecting the dividing means to pivot the breaker plate on movement of the said dividing means and means to move the dividing means comprising a conduit constantly connected to one of the chambers and a source of suction developed by the engine, a spring in said chamber for urging the dividing means in one direction, a second conduit connected to the other chamber, a valve for connecting said second conduit to the intake manifold or to atmosphere, and means for operating the valve to select connection of either said manifold or atmosphere.

References Cited UNITED STATES PATENTS 2,3 83,898 8/ 1945 Udale 123-1 17.1 2,708,918 5/1955 Caddock l23117.l 2,825,320 3/1958 Brueder 123l17.l

FOREIGN PATENTS 101,070 8/ 1916 Great Britain.

WENDELL E. BURNS, Primary Examiner US. Cl. X.R. 12397 

